Revealed: Did Michael Jackson really sing on The Simpsons?

Lisa, it's NOT your birthday: The "Michael Jackson" song was actually performed by Kipp Lennon.

Lisa, it's NOT your birthday: It's a favourite among Simpsons fans, but did Michael Jackson actually sing "Lisa, It's Your Birthday" in his 1991 appearance on the show?

Two years after Michael Jackson's death, the voice of Lisa Simpson, Yeardley Smith, has opened up about being serenaded by the pop star.

And the truth is... she wasn't.

"[Michael] was not allowed to sing on the show, so he literally hand-picked a guy to sing like him," Smith told TMZ.

While Jackson wrote 'Happy Birthday Lisa', which was featured on The Simpsons back in 1991, his record label reportedly blocked him from singing it. Jackson selected a man named Kipp Lennon to sing in his place.

"How unnerving would it be to sing like Michael Jackson in front of Michael Jackson?" Smith said.